Effect of Pressure on the Charge Transfer Spectra of Heavy Transition Metal Hexahalide Complexes

Abstract

The effect of pressure has been measured on the charge transfer bands of seven hexahalide salts of heavy transition metal ions (with 4d and 5d configurations). The lowest energy peaks always exhibited a large red shift with increasing pressure. Higher energy peaks always showed less shift, and in one case actually shifted to the blue. While there are undoubtedly several factors involved, the data are consistent with the assumption of increased spin-orbit coupling at high pressure. The marked broadening of the bands can be discussed in terms of the effect of decreased lattice spacing on the molecular charge transfer.